1. Technical Field
The present invention relates to a nucleic acid extraction method for extracting nucleic acid from a cell.
2. Related Art
In order to extract nucleic acid, it is necessary to disrupt (lysis) the membrane structure of a cell to thereby cause the content of the cell to be extracted outside the cell. A microbe is generally defined as a living organism that is microscopic, or smaller in size, such as a bacterium, archaebacterium, protist, fungus, and so forth. The microbes differ in feature from each other, and bacteria fall into two broad categories, that is, gram-negative bacteria, such as Escherichia coli (E. coli), and so forth, and gram-positive bacteria, such as Bacillus subtilis (B. subtilis), and so forth, on the basis of a difference in the membrane structure of a cell. For example, a cell wall of a gram-positive bacterium has a peptidoglycan layer greater in thickness, and higher in density than that of a cell wall of a gram-negative bacterium. Further, in the case of a fungus such as Candida albicans (C. albicans), and so forth, major constituents of a cell wall thereof is β-glucan, and chitin, and the fungus differs in composition from the bacteria described as above. Accordingly, in the case of making use of enzymatic or chemical method for cell lysis, different protocol is needed for each type of targeted cell. In the case of using an enzyme, in particular, zymolyase is commonly used for fungus in contrast to lysozyme that is commonly used for bacteria. Further, lysostaphin is commonly used for lysis of cell wall of Staphylococcus aureus (S. aureus) among the gram-positive bacteria because lysostaphin is effective in use.